What are geomagnetic storms? which is the first time such watch has been issued in nearly 20 years.

Washington: The National Weather Space Weather Prediction Centre (SWPC) has issued a 'severe geomagnetic storm watch' for this weekend starting from Friday, which is the first time such watch has been issued in nearly 20 years. The alert was issued after five earth-directed coronal mass ejections (CMEs) were observed and expected to arrive by Friday.
Several strong flares have been observed over the past few days by scientists and were associated with a large and magnetically complex sunspot cluster, 16 times the diameter of the Earth. Additional solar activity is also expected from the region. The SWPC has classified this as an "unusual event" and predicted that this may persist till Sunday.
The SWPC predicted that a severe G4 geomagnetic storm could emerge as early as Friday after days of solar activity. The solar storm, which will primarily impact the United States and surrounding countries, is expected to disrupt several services. The SWPC has already notified operators so they can take protective action.
What are geomagnetic storms? The National Oceanic and Atmospheric Administration (NOAA) refers to a geomagnetic storm as a major disturbance of the Earth's magnetosphere that occurs when there is a very efficient exchange of energy from the solar wind into the space environment surrounding the Earth. These storms result from variations in the solar wind that produces major changes in the currents, plasmas, and fields in Earth’s magnetosphere.